Convert Square feet per second to Square millimetres per hour
Convert Square feet per second (ft²/s) to Square millimetres per hour (mm²/h) instantly and accurately.
Conversion Formula
mm²/h = ft²/s × 334450944
About Square feet per second
The square foot per second (ft²/s) equals 0.09290304 m²/s, the imperial base unit for thermal diffusivity analogous to m²/s. It is used in US aerospace engineering and combustion research for highly conductive materials and high-temperature plasmas. Diamond, the most thermally diffusive solid at ≈7 cm²/s, converts to ≈0.0075 ft²/s; silver to ≈0.00167 ft²/s. 1 ft²/s = 3600 ft²/h = 0.09290304 m²/s.
About Square millimetres per hour
The square millimetre per hour (mm²/h) equals 1/3 600 000 000 m²/s, the smallest practical thermal diffusivity unit. It is used in very slow heat-transfer processes such as diffusion through frozen soils or phase-change materials studied over many hours. Heavy clay soils can show diffusivity values of 1-2 mm²/h. 1 mm²/h = 1e-6/3600 m²/s.
Quick Reference Table
| Square feet per second (ft²/s) | Square millimetres per hour (mm²/h) |
|---|---|
| 1 ft²/s | 334451000 mm²/h |
| 2 ft²/s | 668902000 mm²/h |
| 5 ft²/s | 1.672 × 109 mm²/h |
| 10 ft²/s | 3.345 × 109 mm²/h |
| 25 ft²/s | 8.361 × 109 mm²/h |
| 50 ft²/s | 1.672 × 1010 mm²/h |
| 100 ft²/s | 3.345 × 1010 mm²/h |